Repository Archived text title center align (#25767)

Archive text title center align

<details>
  <summary>Screen shots</summary>
  
 Before

![image](https://github.com/go-gitea/gitea/assets/80308335/90182367-4d06-4fc8-b7aa-21c21225d2bd)

After 

![image](https://github.com/go-gitea/gitea/assets/80308335/3dcc0d0d-75f4-415d-afbf-03921075b4db)


![image](https://github.com/go-gitea/gitea/assets/80308335/317d74f8-0ae9-4dc7-9508-1833d2d4f327)


BTW On github

![image](https://github.com/go-gitea/gitea/assets/80308335/1801fd2d-1803-4ee6-8856-ef2f623df2b4)

</details>

---------

Co-authored-by: Giteabot <teabot@gitea.io>

templates/repo/empty.tmpl

@@ -6,7 +6,7 @@
 			<div class="sixteen wide column content">
 				{{template "base/alert" .}}
 				{{if .Repository.IsArchived}}
-					<div class="ui warning message">
+					<div class="ui warning message gt-text-center">
 						{{if .Repository.ArchivedUnix.IsZero}}
 							{{.locale.Tr "repo.archive.title"}}
 						{{else}}